The present invention relates to the plate of a domestic steam iron of standard construction that comprises an ironing element or plate that, by means of a laminated stainless steel covering or other appropriate material, is the component that comes into contact with the garment that is to be ironed; a vaporiser or steam-generating component that is provided with water from a container that is situated in the iron and comprises a vaporisation chamber where the steam is generated and from which the steam passes through a front opening on the vaporiser to the plate and then passes out to the exterior via holes provided on the plate; the heat element components on the plate and the vaporiser, as their names imply, being allocated to the plate and the vaporiser; and the thermostatically controlled regulators of the temperature of the plate and the vaporiser; and the thermal fuses of the plate and the vaporiser being respectively associated with the plate and the vaporiser.
The present subsidiary patent relates to the plate of a domestic steam iron of standard construction that comprises an ironing element or plate that, by means of a laminated stainless steel covering or other appropriate material, is the component that comes into contact with the garment that is to be ironed; a vaporiser or steam-generating component that is provided with water from a container that is situated in the iron and comprises a vaporisation chamber where the steam is generated and from which the steam passes through a front opening on the vaporiser to the plate and then passes out to the exterior via holes provided on the plate; the heat element components on the plate and the vaporiser, as their names imply, being allocated to the plate and the vaporiser; and the thermostatically controlled regulators of the temperature of the plate and the vaporiser; and the thermal fuses of the plate and the vaporiser being respectively associated with the plate and the vaporiser.
In first generation domestic steam irons, the required heating necessary for vaporising the water was generated by the same heating element responsible for heating the plate.
Domestic steam irons of this kind operate at temperatures within the range of 100° C. to 200° C. Within this temperature range and close to 100° C. the steam is not saturated and is designated as ‘wet steam’ since it is close to the limit between the liquid state and steam state, but still comprises a considerable proportion of the liquid phase, and in which a portion of the steam phase passes readily into the liquid phase as soon as there is a relatively small drop in the temperature. Conversely, as the temperature rises a more highly saturated water vapour is obtained which is designated as ‘dry steam’ (approximately, above 120° C.), and the liquid phase becomes increasingly less significant, and in such a manner that at the higher levels of the temperature range indicated, the steam phase becomes increasingly more stable, and, in order to revert to the liquid phase, a significant lowering of the temperature is necessary.
Because of what has been indicated above, when it comes to the actual practice of ironing, there are no real problems when working at a temperature within the higher levels of the said range, where a good supply of ‘dry steam’ is provided, and the high temperature of the iron itself is suitable for the fabric being ironed, and, as a result, the garment does not suffer any damage.
However, when fabrics and delicate garments have to be ironed, it is necessary for the temperature of the ironing element to be at the lower limit of the said working range. As this ironing element and the vaporiser compartment are heated by the one and only heating element, the result is that the steam produced that is available for the ironing procedure is ‘wet steam’. A consequence of this is that, while ironing, a dripping is produced that wets the garment and becomes a nuisance and diminishes the quality of the ironing. This phenomenon is aggravated by the cooling of the ironing implement around its steam outlet holes, which cooling is very significant since it comes very close to the temperature of the steam being expelled and of the ironing element.
At present, a new generation of domestic steam irons is known in which, independently of the assembly comprising the ironing element, the heating element and the thermostatic element which conventional domestic steam irons have, the plate itself incorporates an autonomous vaporiser unit which is integrated with a vaporisation chamber that has a water supply channel connected to the water reservoir of the domestic iron, and the vaporisation chamber of which is fitted with its own heating element which has its own thermostat for regulating the temperature in this vaporisation chamber; the autonomous vaporiser unit has a steam outlet connected to a complementary inlet for steam into the ironing element, and for providing the correct pathway for steam to pass towards the outlet holes. In this way, the production of steam becomes thermally independent of the ironing element, and the iron is provided with dry steam at any temperature, improving the dripping effect and allowing the ironing element to operate at a lower temperature (but still above 100° C.) and improving the quality of the ironing.
However, in these domestic steam irons, there remain certain problems requiring correction or improvement.
One of these problems is the tendency to produce an accumulation of lime-scale which progressively obstructs the passage of the steam to the expellation holes in the plate, due to the lack of a duct available for the passage of steam and/or the lack or insufficiency of filtering means for the lime residues carried by the steam.
Another problem lies in the manner of resolving the passage of the steam between the vaporiser and the plate, being independent units connected to one another. In this respect, the use of a brass cap is known which is simultaneously attached by its ends to such vaporiser and the plate, incorporating at each point of attachment an annular, peripheral, silicone gasket. It is supposed that with this assembly concept the brass cap as well as the silicone gaskets work disadvantageously and in an uneven manner.
Another problem consists in the fact that temperature control of the plate and the vaporiser rely on the presence of thermostats which are insufficiently sensitive and have a slow response time, which results in the continuation of dripping, albeit less, and in the reliability of ironing remaining unsatisfactory.
Another frequent problem is that the steam outlet holes in the plate are distributed over the whole length of the plate, even though they are only close to the side edges of the plate. This means that during ironing with steam the garment retains humidity after the ironing stroke, which is undesirable when ironing delicates.
The present invention relates to a domestic steam iron that corresponds to the general form described above in that it comprises a vaporisation chamber and a plate which, as illustrated in FIG. 1, are proportional in a manner such that, on the one hand, the width of the first is around half that of the second, and on the other hand, the sides of the vaporisation chamber are approximately in a straight line and converge with respect to one other in such a manner that they progressively diverge away from the edge of the plate. Another embodiment of the present invention provides a different relative geometry between the vaporisation chamber and the plate.
Another embodiment of the present invention provides a passage for the steam from the said vaporisation chamber to the plate via a horizontal pipe.
Another embodiment of the present invention relates to a distinctive internal structure of the vaporisation chamber.